Toki pona is changing and it has different branches. That is great! That means it is alive and people is using it. As long as we can understand each other it is fine.

American english and british english are different from each other. They are both english.Formal english and informal youth english are different from each other. They are both english.

-Hello. I need to tell you something: Last night I met my old friend William. He said something along the lines of "I did not expect to see you here" and I was very surprised.

-Hi. I gotta tell you, last night I met my boy Willy, and he was like "I didn't expect you here" and I was like "Whaaaat".

Those phrases are both english. One is formal, the other one is colloquial. That does not make any of them "less english".

Jan Lope is pushing a formal, restrictive grammar aiming to overcome ambiguity based on pu, and creating new rules and tools to fill the gaps. This is good. Other people is pushing a colloquial, natural, easier to use toki pona filling or exploiting this gaps with further utilities. This is also good!

People can talk using a formal, restrictive grammar if they feel comfortable with it. It is useful for learning the language, too, as the inherent ambiguity of toki pona can be hard to grasp sometimes. Then they can shift to a more relaxed way of speaking, when they feel appropriate, and shift back when they need clarification:

tan jan olin mi la mi ponaseme?tan pi jan olin mi la, mi ' pona

For my lover, I'm better.What? (does that means he is the best one his lover could choose, or that he healed for her, or maybe he is better now because she helped him?)For the cause of my lover, I am a better person.

(this example may contain mistakes as I'm still learning)

They are just different registers. Both are good. Use both of them as tools, as colors, not as flags to fight for.

Very nice.But it is still necessary, for all sorts of reasons, to figure out what is going on and to give students (and even not so studious) guidelines so that they can do what they want in their own mode. Lope is too negative, Loki is too positive (anything go so long as we understand -- and even if we don't). So a middle ground, enforcing some rules, letting others slide as dialectal, seems the best policy. And when it all becomes unintelligible, trying to sort it out and get it back on track.

"for" is usually 'tawa', not 'tan', but 'tan' is clear as "because of". It just says different things. 'toki kepeken/lon toki pona' (one of those rules that needs to be enforced at risk of saying really weird things.